A power converting apparatus of an eco-friendly vehicle receives a DC from a high-voltage battery, converts the DC into an AC, supplies the AC to a motor, and controls torque and revolutions per minute of the motor by adjusting intensity and phase of the AC.
In general, the inside of a power converting apparatus can be divided into a power unit that converts a DC into an AC and a control unit that controls the intensity and phase of a current. The power unit is composed of a bus bar through which a current flows, a switch elements converting a current, and a power module and the control unit is composed of a gate board, a control board, and wires transmitting/receiving signals to/from sensors.
The power unit generates electromagnetic waves when a current flows or switching is performed by a plurality of switching elements constituting the power module, and the electromagnetic waves influence the control unit, whereby they may cause a malfunction or may stop the control unit. The control board is a part that is most vulnerable to electromagnetic waves of the parts of the control unit, and power converting apparatuses of the related art have a metallic shield plate to shield the control board from electromagnetic waves.
However, the shield plate has a limit that it only blocks paths to prevent electromagnetic waves from influencing the control board and cannot completely separate the control board from electromagnetic waves. Further, when the paths of electromagnetic waves are not completely blocked due to an improper design of a shield plate, there is a danger in that the control board may generate a malfunction. Further, there is another problem that the manufacturing cost, and weight and volume of a power converting apparatus, are increased due to a shield plate.